http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53039
--- Comment #12 from Jason Merrill <jason at gcc dot gnu.org> 2012-06-11 05:59:25 UTC --- (In reply to comment #11) > The #c10 testcase started failing with > http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=170341 Right. Using DECL_NAME to compare parameter packs doesn't work if one parameter pack can be replaced by another in substitution. In both BType and AType, we have Xs<is_convertible<Us, Ts>::value...>::value, and the appearance in AType ends up replaced by the version from BType, so when we compare the Us to the AType parameter, they don't match. Clearly they should match. I think comparing the decls was my idea, sorry.